Production of the model now known as the Defender began in 1983 as the Land Rover 110, a name which reflected the 110-inch (2,800 mm) length of the wheelbase. The 110 was launched in 1983, and the 90 followed in 1984. From 1984, wind-up windows were fitted (Series models and very early 110s had sliding panels), and a 2.5-litre (153 cu in), 68 horsepower (51 kW) diesel engine was introduced. This was based on the earlier 2.3-litre (140 cu in) engine but had a more modern fuel-injection system and increased capacity. A low compression version of the 3.5-litre (214 cu in) V8 Range Rover engine improved performance. It was initially available in the 110 with a Range Rover LT95 four-speed transmission with an integral transfer case and vacuum-operated differential lock, then later in conjunction with a high strength "Santana" five-speed transmission.